Locksmiths use a procedure known as impressioning to determine what is known as the bitting or key code of an automobile lock. Impressioning is usually preformed on the door lock of a vehicle and is essentially a trial and error procedure using marks made on a key blank by the wafers inside of the lock. Using a file a locksmith will remove material wherever a visible mark appears on the key until the key can open the lock. This process is often used when the original key has been completely lost and no key is available for duplication. Once completed the locksmith can determine the code of the cuts made on the impressioned key. With this code the locksmith can use a key cutting machine that is capable of cutting a key by code to create a new key or he can simply duplicate the key that has been impressioned. However, this process is labor intensive and time consuming and most automobile door locks do not contain all the codes necessary to turn the ignition or trunk. In many cases one or two additional cuts are required to turn the ignition. To complete the key a locksmith will either continue to file down the cut, repeatedly testing the key in the ignition or trunk until the lock opens. Or he will use a software package that will provide the remaining possible code combinations using the code that has been determined from the door lock.
To advance the practice of lock impressioning, what is needed is an Electronic Key Impressioner or (EKI) to reduce the amount of labor and time required to replace a lost or missing key by mathematically calculating cuts for a replacing key using stored programs executed by electronic circuitry based on measurements by an impressioner.